ISRO reschedules Proba-3 launch after detecting 'anomaly'

The satellite will now be launched on Thursday (December 5) at 4.04 pm.

Chennai: The Indian Space Research Organisation (ISRO) on Wednesday postponed, at the last minute, to Thursday the launch of PSLV-C59 carrying Proba-3 spacecraft after an “anomaly” was detected in the redundant propulsion system. 

The launch of the Proba-3 spacecraft into a highly elliptical orbit as a dedicated commercial mission of NewSpace India Limited (NSIL), the commercial arm of Isro, was called-off just an hour before the scheduled take off at 4.08 pm.

The satellite will now be launched on Thursday at 4.04 pm. 

Proba-3 is an In-Orbit Demonstration (IOD) mission of the European Space Agency (ESA), whose goal is to demonstrate precise formation flying. The mission consists of two spacecraft – Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC) -- and they will be launched together in a stacked configuration. 

Josef Aschbacher, Director General, ESA, said an anomaly in the redundant propulsion system of the Coronagraph Spacecraft was noticed as preparations were underway for its launch from the first launchpad of the Satish Dhawan Space Centre in Sriharikota near here. 

“This propulsion system is part of the attitude and orbit control subsystem of the satellite and used to maintain orientation and pointing in space. The anomaly is currently under detailed investigation,” Aschabacher added. 

The use of a software solution by the mission control team at ESA’s ESEC Centre at Redu, Belgium is being evaluated to allow a launch on Thursday at 4.04 pm.  

The double-satellite is the most ambitious member yet of the Proba family of experimental missions and will help uncover the mysteries of the Sun's corona, the ESA said. 

A pair of satellites will fly together, maintaining a fixed configuration as if they were a single large rigid structure in space, to prove innovative formation flying and rendezvous technologies, the ISRO said.

Proba-3 will function as an orbital laboratory, demonstrating acquisition, rendezvous, proximity operations and formation flying, while validating innovative metrology sensors and control algorithms, opening up novel methods of mission control. 

“The two satellites will adopt a fixed configuration in space, 150m apart while lined up with the Sun so that OSC blocks out the brilliant solar disk for the CSC. This will open up continuous views of the Sun’s faint corona, or surrounding atmosphere, for scientific observation,” the ISRO added.